Object in texture and material view appear black
You have a black image in the UV/Image editor that the object is linked to. For the material view, it is because you have that texture applied in the textures tab of the properties window. 

"Solutions" (There isn't actually anything wrong)


In texture paint mode, you can paint onto that texture and change its color.





You can disable that texture to keep it from showing up in the material preview.





You can put a different texture on it. For changing texture mode's display, go to the UV/Image editor and with the object in edit mode (so you can see the UVs), select a different image.